1. Field of the Invention
This invention relates to a combination creeper gear and control system for a transmission and more particularly to a combination creeper gear and control system which is capable of providing extra low creep speeds.
2. Description of the Prior Art
Currently some agricultural tractors employ a transmission which has a creeper gear interposed between a range selector gear and a change speed gear. This creeper gear is positioned on a lay shaft adjacent to the transmission gear arrangement. In such an arrangement, the speed of the input shaft of the transmission, with respect to the creeper gear, is always reduced by the range selector gear and therefore it is difficult to provide the creeper gear as an optional feature on the tractor. Thus, when the creeper gear is disposed downstream of the range selector gear, the drive gear wheel of the creeper gear must be arranged coaxially with respect to the output shaft of the range selector gear so that it also rotates at the reduced speed. Creeper gears of this kind are not synchronized but can be shifted by way of a dog or a sliding gear shift mechanism. If creeper gears of this kind are to be synchronized, the relatively low speed of rotation would result in relatively high torque values, which in turn would have the result that the synchronization means would have to be of heavy duty construction.
These disadvantages are overcome by the present invention wherein a combination creeper gear and control system for a transmission is taught with a creeper gear mechanism positioned upstream and independent of the transmission.
The general object of this invention is to provide a combination creeper gear and control system for a transmission. A more specific object of the invention is to provide a combination creeper gear and control system for a transmission wherein extra low creep speeds are obtainable.
Another object of this invention is to provide a combination creeper gear and control system for a transmission having a range selector gear followed by a change speed gear wherein the creeper gear is upstream and independent of both the range selector gear and the change speed gear.
Still another object of this invention is to provide a combination creeper gear and control system for a transmission which is synchronized.
Other objects and advantages of the present invention will be more apparent from the following description and the drawings.